Antenna



April 8, 1941.

Filed April 30, 1938 JHIFTER I 1' i SHIFTER VAR/ABLE TRANSFORMERINVENTOR ATTORNEY Patented Apr. 8, 1941 ANTENNA Wilhelm Moser, Berlin,Germany, assignor to Telefunken Gesellschaft fur Drah-tlose Telegraphicin. b. H., Berlin, Germany, a corporation of Germany Application April30, 1938, Serial No. 205,198 In Germany May 4, 1937 10 Claims.

For transmitting and receiving high-frequency waves antennas are knownwhich as compared with the customary short wave antennas operate withtravelling waves. These antennas ordinarily consist of one or severalconductors connected at one side to the transmitter or receiver andwhose free ends are either connected to each other or to the groundacross an end resistor, which is equal to the wave resistance of theantennas. The energy coming from the transmitter is then in partradiated along the antenna conductor and the remaining part is consumedin the end resistor. These antennas have the disadvantage that asubstantial part of the energy conducted thereto is destroyed in theterminal resistor.

This disadvantage is overcome in accordance with the invention in thatthe antenna is coupled at both ends to the transmitter or receiverinstead of being connected thereto at one end only. In this case noterminal resistor is required since the energy appearing at the ends ofthe antenna is again passed to the input. The transmitter need thensupply only the radiated part of the energy so that the efliciency oithe arrangement will thereby be greatly increased.

The present invention will be clearly understood by reference to thefollowing detailed description which is accompanied by a drawing whichshows diagrammatically an embodiment of the invention.

The figure shows a rhombic antenna comprising the two bent conductors Iand 2 connected at one end to the transmitter 5 across a connection line3 and coupling arrangement 4. Instead of connecting to each other acrossa terminal resistor in the manner known in the prior art, the other twoends of the antennas have, in accordance with the invention, likewise anenergy line 6 connected thereto by means of which the non-radiated partof the energy is again returned to the coupling arrangement 4 and hence.also, to the input of the antenna. The energy must be returned in such amanner that this returned energy and the energy coming from thetransmitter have the same phase and the same amplitudes. The phaseequality can be provided either by a suitable choice of the length ofthe line 6, or by a phase shifting device 1 while the amplitude iscontrolled for instance by transformation in the transformer 8.Additionally. arrangements 9 serving for adjustment of the amplitude andphase may also be placed in the line 3. The proportion between theamplitude of the returned wave and the amplitude of the primary wave mayalso be attained by adjustment of the coupling arrangement 4. Care mustbe taken that matching exists at all places of the entire arrangement.

Aside from the gain in energy the described arrangement has the furtheradvantage that the proportions between the currents on the antenna canbe adjusted to in any desired manner and that thereby much morefavorable conditions of radiation can be achieved,

The return line 6 need not necessarily be coupled directly as shown butany number of intermediate organs or transformers may be employed. Theentire antenna can be matched with the energy line In likewise byadjusting the coupling of the transformer 4.

I claim:

1. A rhombic antenna comprising a pair of conductors having their endsadjacent and the midpoints separated, a transmission line, means forcoupling said line to said antenna at one pair of adjacent ends wherebytravelling waves are set up in said antenna, a second transmission lineconnected to the other pair of adjacent ends and means fon coupling saidsecond line to said first mentioned means.

2. A rhombic antenna comprising a pair of conductors having their endsadjacent and the midpoints separated, a transmission line, means forcoupling said line to said antenna at one pair of adjacent ends, asecond transmission line connected to the other pair of adjacent ends,means for coupling said second line to said first mentioned means andmeans for adjusting the phase relationship between the currents in saidsecond transmission line and said first mentioned means.

3. In combination, a travelling wave antenna, means for energizing saidantenna connected to one end thereof and means connected to the otherend of said antenna for preventing reflection of energy from said end,said means comprising a transmission line connected to said other endand coupled to said first mentioned means whereby energy arriving atsaid other end is reapplied to said antenna at said one end.

4. A rhombic antenna comprising a pair of conductors having their endsadjacent and the midpoints separated, a transmission line, means forcoupling said line to one pain of adjacent ends, a second transmissionline connected to.

the other pair of adjacent ends, means for coupling said second line tosaid first line and means for adjusting the phase and amplitude of thecurrents in said second line.

5. A travelling Wave antenna having a length at least as long as thelength of the operating wave, said antenna having an axis arranged alongthe line of a desired direction of communication, a first transmissionline, means for coupling said transmission line to said antenna at itsremote end With reference to said direction line, a second transmissionline coupled to said antenna at its other end and means for couplingsaid second transmission line to said first mentioned means.

6. A rhombic antenna comprising a pair of conductors having their endsadjacent and the midpoints separated, means for energizing said antennaconnected to one pair of adjacent ends, a transmission line connected tothe other pair of adjacent ends for feeding energy from said second pairof ends back into said first pair of ends, and means for adjusting thephase and amplitude of currents in said transmission line.

'7. In combination, a travelling Wave antenna, means for energizing saidantenna connected to one end thereof and means connected to the otherend of said antenna for preventing reflection of energy from said end,said means comprising a transmission line connected to said other endand coupled to said first mentioned means whereby energy arriving atsaid other end is reapplied to said antenna at said one end and meansfor adjusting the phase of said reapplied energy.

8. A travelling wave antenna having a length at least as long as thelength of the operating Wave, said antenna having an axis arranged alongthe line of a desired direction of communication, a first transmissionline, means for coupling said transmission line to said antenna at itsremote end with reference to said direction line, a second transmissionline coupled to said antenna at its other end, means for coupling saidsecond transmission line to said first mentioned means and means foradjusting the phase of the currents in said second transmission line.

9. In combination, a travelling wave antenna, means for energizing saidantenna connected thereto at one point, means connected to said antennaat another point remote from said one point for receiving energyarriving thereat and means for reapplying said energy to said antenna atsaid one point in phase with the energy applied thereto from saidenergizing means.

10. In combination with an antenna characterized in that wave energy isapplied thereto at one point and continuously progresses to anotherpoint on said antenna of means coupled to said other point for receivingenergy arriving thereat and means for reapplying said received energy tosaid antenna at said one point with a predetermined phase and amplitude.

WILHELM MOSER.

